Bio-renewable thermal energy heating and cooling system and method

ABSTRACT

The present invention is directed towards a bio-renewable thermal energy heating and cooling system which is capable of rejection, reclamation and cogeneration. The refrigeration system of the present invention utilizes one or more evaporators and one or more condensers to transform thermal energy in the form of waste heat in one environment for use in another environment. The hot and cold sides of the refrigeration process may be split for multiple applications for increased utilization of the system energy. The environmental variables are balanced so as to optimize the properties of the refrigerant and the capabilities of the system compressor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 of a provisionalapplication Ser. No. 60/804,148 filed Jun. 6, 2006, which application ishereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 7,040,108 ('108) described a method of recovering thermalenergy from various environments and utilizing it in a process orstoring it for later use. The basic configuration in the '108 patentutilized a single evaporator and water cooled condenser with acompressor, expansion device, receiver, circulating pump and hot storagetank. This patent emphasized the heating capability of the refrigerationprocess and extended the use of refrigeration technology towards themaximum utilization of the refrigeration cycle for its heating affectswithin a given application. The refrigeration cycle was defined as aprocess involving a compressor, heat exchanger (condenser), expansiondevice, and evaporator. Thermal energy was to be collected in theevaporator from air or from liquids or slurries and was generally to beplaced into a liquid stream or storage device where it could also beused to heat a space or process. The '108 system operated in a singlemode, that is, reclamation.

SUMMARY OF THE INVENTION

The present invention extends the teaching of U.S. Pat. No. 7,040,108 toinclude a formula or methodology for application of the refrigerationprocess to further enhance or optimize the utilization and control ofrefrigeration for the transformation of thermal energy available in oneenvironment/media to another environment/media. This is not the simpletransfer of thermal energy from location to location but the efficienttransformation of thermal energy from one condition to one or moreconditions desirable for a given application. This is accomplishedthrough the balancing of the environmental variables with the propertiesof the refrigerant and the capabilities of the compressor.

For example, in a meat processing facility, chillers are used tomaintain workplace temperatures that are suitable for safe processing ofthe meat and boilers are used to heat kill process water and wash water.The system of the present invention will provide the chilling while alsoproviding a fixed temperature of liquid refrigerant to the expansiondevice and generating heated water for the kill process and the washdown. The fixed liquid refrigerant temperature helps to optimize theperformance of the compressor where most chiller condensers arecurrently exposed to the variability of the ambient air temperaturewhich will cause compressor performance to vary off of the optimalcondition.

The combination of compressor configuration, refrigerant, condenserconfiguration, expansion device/configuration, and evaporatorconfiguration are driven by the requirements of the application and thenature of the refrigerant selected. One goal of the system configurationis to achieve the most desirable balance of refrigerant and lubricantconditions at the compressor while optimally utilizing thermal energysources and thermal energy sinks available in the application.

With this teaching and methodology the use of refrigeration for heatingand cooling is extended to new horizons whereby with new refrigerantsand refrigeration system configurations we will have capability todisplace a significant portion of the world's combustion based furnaceor boiler capacity, while providing refrigeration or cooling to the sameapplication. This technology may also lead to the co-location ofcomplimentary energy-intensive applications to help reduce or eliminatedependence on external fuel sources.

One aspect of the present invention is the utilization of multipleevaporators and multiple condensers tied to a single compressor so as toincrease the utilization of waste heat.

In another aspect of the present invention, refrigerant heat is splitfor multiple uses. For example, the heat can be used for generatingwater, liquid or steam that is hotter than the condensing temperature ofthe refrigerant. Producing steam represents use of the hot path toproduce a phase change on the environment side of the refrigerationprocess.

In another aspect of the present invention, a circulating loop with awater tank, pump and a condenser/heat exchanger provides control to thehead pressure, so as to provide control and storage of highertemperature fluid, and to control the subcooling temperature for theimprovement of the evaporator heat collection capacity, and to uniquelyimprove compressor efficiency. While subcooling has been used in theprior art, such use is provided by robbing a portion of the systemrefrigerant to cool the remaining liquid refrigerant prior tointroduction into the expansion device to help improve heat collectioncapacity in the evaporator. In comparison, the present invention useswater or a process stream to do this subcooling, rather than therefrigerant. This improves performance by collecting additional usefulheat in the process stream through the subcooling of the refrigerant, aswell as boosting the heat collection efficiency of the evaporator. Acirculating loop provides the basis for control of subcooling conditionsto maintain higher compressor efficiency.

Another aspect of the present invention relates to desuperheating, whichis known in the prior art, but only for the purpose of extracting theheat available from the superheat in the high temperature refrigerantvapor to heat water, while the remainder of the heat is rejected. Thepresent invention utilizes the full heat path towards heating a liquidprior to allowing rejection or switching to a heating application from asecondary priority, which is unique, and specifically not in conjunctionwith a circulating and storage loop used for process control. Thisinvention utilizes the full heat path as a priority and utilizes thedesuperheating segment to produce and/or store water or fluid attemperatures above the condensing temperature of the refrigerant beforeallowing rejection or lower priority use. Splitting the refrigerant hotside for various uses or controls significantly advances energyutilization beyond the prior art, which focused on rejection of therefrigeration heat.

A further aspect of the present invention is the splitting of the coldside of the refrigeration process, in conjunction with splitting of thehot side. Evaporators in series or in parallel provide certainchallenges, such as control of pressure in the suction line when twoparallel evaporators operate at different temperatures and pressures.Evaporators in series are a challenge to supply cooling at temperaturesthat are suitable for both environments, since the outlet temperaturedrives the control of the temperature of the refrigerant in allevaporators.

With the system of the present invention operating in the reclamationand cogeneration mode, a significant thermal emission reduction isprovided, since the thermal energy that previously was going to bewasted is now recycled back into the bio-renewable process. The formulathat has been developed for controlling the environmental balance ispremised upon the first and second laws of thermodynamics, so as tobalance the energy of the system of the present invention from both therefrigerant and environmental perspectives, thereby achieving resultsand control of process beyond traditional refrigeration processes.

The system has the ability to heat potable water, cool interior spaceareas, use the hot water for heating interior space areas, recyclethermal energy by cooling one area while heating a second area, and savesignificant amounts of energy while completing these tasks.

A three-way reclaim valve is used to switch between the water-cooledcondenser and the external condenser. This valve along with a checkvalve draws the refrigerant out of the external condenser and back intothe system and keep the refrigerant from pooling in the externalcondenser. This allowed the system to provide heating, cooling and waterheating.

The ability to control the condensing temperature at the temperature ofthe water tank via the circulation system is a unique characteristic.The use of water for control, while also using the heat for usefulheating, is unique. The temperature of the water in the tank sets thehead pressure of the compressor (i.e. corresponding to the condensingtemperature of the refrigerant).

The limitation of the single condenser, is overcome with a system thatused two condensers in series each with its own tank and circulatingsystem. This allows the first condenser to absorb all of the energy itcould before the second heat exchanger begins to absorb energy. As thefirst heat exchanger system reaches the maximum condensing temperature,the majority of the heat is being captured by the second heat exchanger.As the system continues to operate, the water in the first circulationloop becomes hotter than the condensing temperature and the refrigerantentering the second heat exchanger is now accepting some superheatedvapor refrigerant. The temperature of the first loop is above thecondensing temperature of the refrigerant. This allows the system toheat water to over 200 F in a batch mode operation.

For continuous mode operation, cold water is introduced at the inlet ofthe circulating pump of the second circulating loop to allow the systemto operate at a condensing temperature attributable to the mixturetemperature of the hot water in the tank and the cold water entering thesystem. This allows the system to operate at lower head pressures whilegenerating higher temperatures. A reciprocating compressor operating onR22 can operate in continuous flow mode at temperatures as high as 130 Fwithout exceeding acceptable head pressures. This would be the resultwhether the system had one or two condensers. Applicants call thephenomenon tempering.

The same flow strategy is also applied to the hot water entering thefirst circulating loop. If the hot water is introduced at the suction ofthe circulating pump, the first condenser sees a mixture temperaturethat is lower than the tank temperature. Thus the system can absorb moreheat at a given condition in the first condenser due to the greatertemperature differential. The first circulating loop controls the headpressure of the compressor, thereby increasing compressor efficiency.

The system performs better when the first condenser circulating loop isat or below the maximum condensing temperature of the refrigerant in thesystem—which for the given system was around 125 F—and the secondcirculating loop is still relatively cool. The second loop is removingadditional heat and sub-cooling the liquid refrigerant. The secondcirculating loop controls refrigerant subcooling, which also improvesefficiency of the compressor.

Subcooling provides two benefits:

-   -   1. The system gains the heat of subcooling for useful heating of        the water.    -   2. When the refrigerant is expanded in the TX valve there are        fewer flash gas losses (i.e. there is more liquid refrigerant to        boil in the mixture inside of the evaporator and the heat        transfer into the evaporator can be increased).

A third circulating loop may be provided for controlling desuperheating.

Thus, a second use for the dual condenser mode operation is to providesubcooling to increase the capacity of the system. It then follows thata third condenser can be used to provide both the ability to heat liquidto higher temperatures and subcool the refrigerant for the same system,yielding improved system performance.

Use of multiple evaporators and multiple condensers in parallel circuitsto provide any combination of heating and/or cooling and the use ofmultiple condensers and circulating loops in series within a circuit canbe expanded for use of configurations in whatever capacity is needed.Any number of circuits can be applied or any number of condensers orevaporators in series to not only satisfy the requirements of anyapplication but to optimize the utilization of the refrigeration systemand maximize the cost benefit of the system installation for a givenapplication.

Thus, a formula has been developed which describes the nature of thesystem in terms of both its physical and economic variables. Since arefrigeration system has never been applied in this manner, this formulais unique and describes the nature of the system for a wide variety ofapplications. The formula parameters allow the system to be evaluated asa viable alternative in the thermal energy infrastructure of the world.

The thermodynamic formula inputs bio energy in the form of ambient airand recycled energy balanced on the capacity of the refrigerant and thecompressor by first applying the energy into the application andrejecting the remaining energy in order to balance on the capacity ofthe refrigerant and compressor to all new levels.

As used in this application, “environmental thermal energy” is definedas thermal energy that is available and exists naturally or has beenreleased to an environment by an exothermic process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of a basic prior art heating, cooling andhot water configuration according to the '108 patent.

FIG. 2 is a schematic drawing of another embodiment of a prior art basicheating, cooling and hot water configuration according to the '108patent.

FIG. 3 is a schematic drawing of an embodiment of a basic heating,cooling and hot water configuration according to the present invention.

FIG. 4 is a schematic view of an embodiment of the present inventionshowing heating, cooling and hot water utilizing multiple heat sinks.

FIGS. 5A and 5B are schematic drawings showing alternative embodimentsof a heating, cooling and hot water system having a warm water heat sinkaccording to the present invention.

FIG. 6 is a schematic drawing of another embodiment of a heating,cooling and hot water system having thermal loops and thermal storageaccording to the present invention.

FIG. 7 is a schematic drawing of yet another embodiment of a heating,cooling and hot water system with mixed superheat cogeneration andrejection according to the present invention.

FIG. 8 is a schematic drawing of still another embodiment of a heating,cooling and hot water system utilizing superheated liquid according tothe present invention.

FIGS. 9 and 10 are schematic drawings of further embodiments of aheating, cooling and hot water system with subcooled liquid according tothe present invention.

FIG. 11 is a schematic drawing of another embodiment of a heating,cooling and hot water system with superheated heated liquid andsupercooling according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Formula for ControllingEnvironmental Balance with the Refrigeration Cycle

Applicants have developed a universal formula necessary for balancingthe cogeneration of heat and cold within the refrigeration cycle withthe constraints of two (or more) environments to be affected orcontrolled by the refrigeration process.

The variables must be balanced relative to the requirements of a givenapplication of the system. The first consideration is the choice of arefrigerant that has physical properties that will allow evaporation andcondensation at temperatures that meet the demands of the applicationwithin the compression ratio and operating temperature limitations ofavailable compressors and compressor oils. There are many materials andmixtures of materials having refrigerant characteristics. As a broaderarray of application conditions are considered, new refrigerants will beselected or created to harness the efficiencies of the refrigerationcycle. Once a suitable refrigerant is selected, the formula can beapplied along with the appropriate engineering principles to select ordesign the refrigeration system components that will properly balancethe refrigeration cycle and withstand the rigors of the application.

The basic formula can be written in a number of formats. For arefrigeration process using direct expansion in terms of the applicationenvironments and electricity use:

-   -   (1) Desired change in environmental conditions at location of        evaporators−Evaporator side piping losses and heat        gain+Electricity consumed−Compressor and motor losses=Desired        change in environmental conditions at location of        condensers−Condenser side piping and heat losses.

This relationship can also be represented in terms of the of therefrigeration cycle itself. For example, equation 1 can be written asfollows:

-   -   (2) Evaporator energy collected−Evaporator side piping losses        and heat gain+Compressor work=Condenser energy        rejected−Condenser side piping and heat losses.

These relationships share the following sub-relationships:

-   -   (3) Evaporation energy collected=Desired change in environmental        conditions at location of evaporators.    -   (4) Condensation energy rejected=Desired change in environmental        conditions at location of condensers.    -   (5) Compressor work=Electricity consumed−Compressor and motor        losses.

The generic terms utilized in the foregoing equations will be derived inthe terms of the specific application or refrigeration cycle and willconform to the laws of the conservation of mass and energy withconsideration of the significant losses. These equations are utilized todetermine the practical scale and configuration of refrigeration systemthat will maximize the utilization of both heating and cooling resourceswhile the refrigeration cycle is in operation and thus maximize theoverall benefit of the installed system.

The formulae provides the basis for designing the system to match theenvironmental requirements with the refrigeration system requirementsand optimize operating efficiency for simultaneously utilizing both theheating and cooling sides of the refrigeration cycle. In comparison, thegoal of prior art systems was generally to maximize performance whilesatisfying either the heating or the cooling side.

Classes of Refrigeration Application.

There are three classes of refrigeration application based on theutilization and efficiency of the refrigeration process: Rejection,Reclamation, and Cogeneration.

A. Rejection

Historically, the majority of refrigeration applications fall into therejection class. In rejection, one side of the refrigeration process isalways wasted. For example, an air conditioner transports heat frominside of a building to the outdoors. The desired benefit is the coolingof the space, while the heat (including the electricity used to run themachine) is displaced or rejected to the environment. Similarly mostrefrigerators, chillers, and freezers will simply reject the heat theyare collecting to the environment where the condenser is located withoutconsideration of the utilization of the heat for any useful purpose. Anair to air heat pump is similar in that it cools the space whilerejecting heat in the summer, and heats the space while rejecting coldin the winter. Rejection refrigeration systems are the least efficientsystems since they utilize energy to either heat or cool, but neverboth. Rejection systems have their place since they provide value to aprocess that pays for itself through product protection or production.In many applications however, rejection systems such as chillers andfreezers exist along side of boilers or furnaces which provide space andprocess heating based on combustion. These applications are candidatesfor conversion to reclamation or cogeneration refrigeration.

B. Reclamation

With volatility in energy prices, and uncertainty regarding the balancebetween energy supply and energy demand, more and more refrigerationsystems are utilizing some form of reclamation. In reclamation, someportion of the heating or cooling that may have historically beenrejected is captured and reused for some useful purpose. Collecting heatfrom a waste stream of an application and using it to heat water, space,or some other process stream in the application is reclamation, asdescribed in U.S. Pat. No. 7,040,108. Collecting heat from the exhaustof an animal confinement to heat the confinement or collecting heat outof the waste water or drier vent exhaust of a laundry to heat wash waterare specific examples. In reclamation, the refrigeration system is oftendesigned or optimized for utilization of one side of the refrigerationcycle while the other side is utilized as much as possible, but notnecessarily all of the time or to the fullest extent possible.

The time dependent nature of many processes and the change of seasons isaccommodated by the present invention wherein the refrigeration processis designed with additional flexibility to allow it to be utilized moreefficiently and to a greater extent within a given application,including the need for multiple evaporators and multiple condensers tomeet the priorities and time dependent requirements of the application.A reclamation application may include periods of operation wherepriorities require rejection and may at times operate in cogenerationmode (discussed below). For example, Applicants' system installed in ahome will operate in cogeneration mode when heating potable water whileproviding comfort cooling. The same system will however switch torejection mode when the potable water is heated to its limits and morecomfort cooling is required. If in the same home application, theexternal evaporator is positioned so that it can take advantage of thedrier exhaust and bathroom and oven exhaust fans then the system willoperate in reclamation mode during the heating season or while heatingwater during the cooling season when there is no call for comfortcooling. Since the system is capable of operating in this variety ofmodes, it enjoys the potential of annual performance that exceeds thatof many conventional refrigeration based heating or cooling systems.Several examples of reclamation configurations are described below withrespect to the drawings. A unique characteristic of each of thesesystems is that when it operates in reclamation mode, it utilizes 100%of the heating side of the refrigeration cycle. Most reclamation systemsonly utilize a fraction of the heating capacity. A home heating andcooling system falls into the reclamation category since it may at timesuse rejection, reclamation or cogeneration, which is better than purerejection but not as good as pure cogeneration.

Cogeneration

When both the cooling and the heating side of the refrigeration cycleare fully utilized within a process, the application is calledcogeneration. As mentioned in the reclamation section above, an exampleof cogeneration is when a refrigeration system is used to providecomfort cooling while heating potable water. This effective utilizationof the resource can be extended in a housing or hotel application if thesame system can be used to heat a swimming pool and/or hot tub. However,due to daily and seasonal variability in outdoor atmospheric conditions,housing applications are rarely pure cogeneration applications. Purecogeneration applications will mostly be found in agricultural,commercial and industrial applications where both cooling and heatingare used to produce a product. In an ethanol plant for example, heatrejected from the cooked mash on its way to fermentation or from thefermentation process itself may be collected and used to heat the cookwater or to heat the condensate returns for the boiler. In the future,advances in refrigerants and refrigeration equipment may allowrefrigeration systems to operate at temperatures that will allowrefrigeration systems to displace the boiler. Power plants, bio-dieselplants, chemical and petroleum refineries, commercial laundry/drycleaners and a host of other energy intensive process orientedindustries provide opportunities for cogeneration with a refrigerationsystem.

The configurations shown in the drawings are examples of refrigerationsystems where the formulae described above are used to maximize thereclamation and cogeneration opportunities in an application.

The goal is to maximize utilization of a balanced refrigeration cycle ina configuration that will minimize energy consumption and maximizeefficiency and value to the application. The systems are able to utilizethe optimal combination of rejection, reclamation, and cogeneration asdriven by the requirements and limitations imposed by the application.The systems are capable of utilizing all three classes of operationwithin the same installation.

The Bio-Renewable Reverse Thermal Energy Nature of the System

Historically the refrigeration process has been thought of as a simpletransferring of energy from one location to another at the expense ofelectricity to operate the compressor. The present invention endeavorsnot to simply transfer thermal energy, but through controls and systemdesign, to transform thermal energy relative to its most desirablecondition in a specific application given the constraints andcapabilities of the refrigerant, compressor oil and the equipment. Thisis evident for example in the ethanol process described previously as anexample of cogeneration. The fermentation process requires a fixed 95°F. while the cooked mash is held at 180° F. Fermentation gives off heatas the bacteria metabolize sugar into alcohol. The mash is maintained(excess heat is collected) by the system and transformed into 130° F. to180° F. water depending on the design of the refrigeration process.

The invention is capable of transforming electricity from any sourceinto thermal “bio-energy” through reuse of thermal energy that wouldhistorically have been wasted to the environment and through reductionof toxic emissions associated with conventional combustion based heatingsystems. For example, in a conventional ethanol plant, the cook water isheated using a natural gas, coal, or biomass fired boiler. The excessheat in the cooked mash must be removed before it can be prepared forthe fermentation process. This historically has involved use of heatexchangers to provide heating to other parts of the process but alsorequires additional cooling either from a chiller or cooling tower tofinish the cooling process, since the mash must be colder than mostother stages of the ethanol production process. This is also true formaintaining the fermentation process at 95° F. Thus a fuel is burned toheat a process stream and the heat is then rejected to the environment,or a biological process creates excess heat which is rejected to theenvironment. This mode of operation is prevalent in most industriestoday because historical energy prices and energy supplies have allowedit and until now there has not been an economical way to utilize the lowgrade “waste” heat. With Applicants' system however, the energy thatwould be wasted can be reclaimed to provide the desired cooling andheating affects simultaneously. Also, as technology and refrigerantsadvance, it will be possible to more precisely match the desiredoperating conditions on both sides of the refrigeration cycle.

The system displaces direct fired sources of heating and theirassociated emissions. Since the wasted energy and solid and gaseousemissions would have otherwise been emitted into the environment, thethermal energy reclaimed by the new, inventive system is bio-energy. Abio-energy system also exists when the energy that is reclaimed isderived from living organisms (such as in animal confinements, alcoholproducing bacteria or incubating eggs). The system will inherentlydisplace carbon dioxide (CO₂), carbon monoxide (CO), and nitrogen oxide(NO_(x)) emissions from all carbon based combustion processes and itwill displace sulfur dioxide, mercury and ash emissions from oil, coal,solid waste or biomass combustion. Given the system displacement orreduction of CO₂, SO₂ and other emissions, it may be possible in thefuture to qualify projects for the production of emissions credits(currently SO₂, NO_(x), Hg, and CO₂) which have a marketable value inthe present U.S. cap and trade emissions reduction strategy. The extentof the displacement of emissions and the ecological impact is measuredrelative to the renewable energy nature of the system within anapplication at a specific location.

The renewable nature of this bio-energy can be derived by comparing theefficiency of the system with the efficiency of thermal power plantsthat generate the electricity for the application site. Thermal plantsinclude fossil fuel fired plants, nuclear plants, biomass fired plants,solar thermal plants and geothermal plants. All of these types ofgeneration emit significant amounts of waste heat into the environment,and the combustion based systems produce large quantities of combustionproducts that contribute to air and water pollution. The efficiency ofthermal generating plants is characterized by the heat rate which isdefined as the Btu input of fuel (or thermal energy) per kWh ofelectricity output. The system operation in reclamation or rejectionmode can similarly be characterized as the Btu of heat output per kWh ofelectricity input (the reverse thermal characteristic). If the systemperformance (Btu output/kWh input) is greater than the average heat rate(Btu input/kWh output) of the thermal electrical generating system, thenthe ratio of the two represents the renewable contribution of the systemoperation.

For example, if Applicants' system operates at 12,000 Btu heat outputper kWh electricity input while the thermal generating system isproducing electricity at 9,000 Btu/kWh, then the Applicants' system iscontributing (12,000/9,000−1)*100=33% renewable thermal energy (i.e. 1unit of energy provides 1.33 units of energy for a desired purpose). Theaverage local Btu/kWh heat rate of the generating system will vary asdifferent generating units with different efficiencies are used to meetload. So the renewable energy contribution will vary over time as theheat rate of the generating system varies. However it can be seen thatthe system provides a new incentive to work towards driving the thermalgenerating system heat rate to lower values.

To demonstrate the impact of reducing the heat rate for thermalgenerating systems, for example, let's apply a 7000 Btu/kWh thermalgeneration heat rate. This is in the range of newer combined cyclenatural gas fired power plants. The renewable energy contribution ofApplicants' system becomes (12000/7000−1)*100=71.4% (i.e. 1 Btu ofenergy provides 1.714 Btu of thermal energy). This implies that byshifting natural gas and propane use from direct combustion inresidential, commercial, and industrial applications to use in combinedcycle power generation systems while at the same time applyingApplicants' system technology, we can significantly reduce the amount ofwaste thermal energy and the amount of combustion products emitted intothe environment. To further drive this point, assume for example thatthe renewable energy contribution formula that is an alternative toApplicants' system will operate at 100% efficiency (i.e. subtract 1.0from the ratio). In reality, a direct combustion system would usuallyhave a conversion efficiency in the range of 80% to 93% which means thatan additional 7% to 20% of the heat energy that would have been used(and its associated emissions) would have been lost to the environmentcompared to use of the system. Another way to say this is that one Btuof natural gas or propane provide 0.8 to 0.93 Btu of useful heating.Therefore, for the sake of comparing alternatives, we subtract theefficiency of the direct combustion system from the efficiency of theApplicants' combination/combined cycle generating system to determinethe renewable energy contribution adjusted for the competing alternative(i.e. if the alternative is a 93% efficient boiler the renewablecontribution is (12000/7000−0.93)*100=78.4%. This implies that thesystem will produce 1.784 Btu of useful heating per Btu of useful heatthat would have been provided by a 93% efficient direct fired boiler.

Applicants' system in a reclamation or cogeneration scenario willtypically operate in the range of 11260 Btu/kWh to 13650 Btu/kWh, andnew advances are expected to increase the upper limit. As the reverseheat rate increases, the overall bio-renewable impact of the system willincrease proportionally. A system running at 13650 Btu/kWh running onelectricity from a gas fired combined cycle that will displace a 93%efficient gas fired boiler will produce a renewable contribution of(13650/7000−0.93)*100=102% (i.e. 2.02 Btu of useful heating will begenerated from a Btu of gas fired in the combined cycle plant andamplified by the system relative to 0.93 Btu of useful heating if thesame Btu was directly fired in the 93% efficient boiler).

Since not all electricity generation comes from thermal sources, somecorrection should be made for the affect of non-thermal electricitysources. Non-thermal renewable energy sources have little if anyairborne or thermal emissions and include technologies like wind, wave,hydro and solar photo-voltaic power. The impact of non-thermal renewablegeneration on the Applicants' system renewable contribution will beproportional to the fraction of the total mix of generation producedfrom non-thermal sources. However, the contribution of the Applicants'reverse thermal process and system relative to a non-thermal electricitysource is better described based on the coefficient of performance (COP)or Btu of heat output per Btu of electricity used by the Applicants'system. The units operating in reclamation and cogeneration mode aregenerally capable of operating at a COP of 3.3 or greater. This level ofCOP is also possible in rejection mode, however the temperature of theheat source such as outdoor air on a very cold winter day during theheating season when the system is running in rejection mode can degradethe COP to levels as low as 1.0. For example, assume the system isoperating in reclamation mode at a COP between 3.3 and 4.0. A COP of 3.3corresponds to a reverse heat rate of 11262 Btu/kWh while a COP of 4.0corresponds to a reverse heat rate of 13650 Btu/kWh (i.e. 11262/3413=3.3and 13652/3413=4.0 where 3413 is the conversion constant between Btu andkWh (i.e. 1 kWh of electricity will provide 3413 Btu of thermal heatingfrom a resistant electric heater). At a COP of 4.0, the unit inreclamation mode will be generating 4 Btu of thermal energy for aprocess for every 1 Btu of electricity consumed. Thus, Applicants'system multiplies the thermal capacity of electricity generated fromnon-thermal sources by a ratio equivalent to the COP.

The total renewable contribution of Applicants' system in a generationmix that includes non-thermal generation is represented in the followingexample. Take the 13562 Btu/kWh RASERS, the natural gas fired combinedcycle power plant operating at 7000 Btu/kWh heat rate and a non-thermalrenewable energy contribution of 10% competing with a 93% efficientdirect fired boiler. The renewable energy contribution of our systemthen becomes (13562/(0.9*7000+0.1*3413)−0.93)*100=112.56%. As thethermal generation heat rate is reduced and as the non-thermalcontribution is increased this formula will be reduced to the COP of thesystem. The minimum possible heat rate of the thermal energy systems is3413 Btu/kWh since that would mean that they were operating at aconversion efficiency of 100% (i.e. 1 kWh=3413 Btu).

When Applicants' system operates in cogeneration mode, then therenewable contribution arguably becomes equal to the COP, since thecooling affect would have been required regardless of whether thethermal heating affect was utilized or not. In-other-words if youproduce and use the energy for the cooling affect of the system, thenthe heating affect, if it is fully used, comes for free.

The above discussion demonstrates that the Applicants' system allowsthermal energy based electricity generation systems to producebio-renewable thermal energy when the conversion efficiency (heat rate)of the electricity generation system is combined with the conversionefficiency (reverse heat rate) of the Applicants' system. It was alsoshown that the Applicants' system effectively multiplies the renewablecontribution of non-thermal renewable electricity sources by the COP ofthe Applicants' system. Also, Applicants' system operated incogeneration mode has a bio-renewable thermal energy contribution equalto the COP of the system.

The assumptions made regarding heat rates and efficiencies are withinthe range of nominal performance for thermal systems in operation today.The renewable contribution may infer that the efficiency of the combinedsystem exceeds 100%. However, Applicants' system does not create energy,but rather transforms thermal energy that would normally be wasted orexhausted into the environment into useful thermal energy. Therefrigeration cycle, through proper use and control of the phase changeproperties of a refrigerant, amplifies a small input of energy(electricity) into a larger quantity of thermal energy available for usein a variety of applications.

There will be additional ecological benefits of displacing direct firedthermal heating systems with the Applicants' system besides thereduction in the emission of thermal energy and products of combustion.One example is the reduction in use of makeup water for boilers andcooling towers or evaporative coolers. Another is the reduction in useof scale and biological water treatment chemicals for the boiler and thecooling towers. In consideration of all these things, the environmentaland economic footprint of fossil fuel utilization can be significantlyreduced through implementation of the Applicants' system. As natural gasand propane used for direct thermal heating of onsite industrial,commercial, agricultural, and residential applications is displaced withApplicants' system technology, more natural gas and propane will beavailable for cleaner, more efficient combined cycle gas firedelectricity generation. Since Applicants' system technology generatesbio-renewable thermal energy it may also be classified according to itsbio-renewable nature to allow it to participate in the renewable energyincentives programs and renewable energy credit markets with at leastthe following benefits:

-   -   (1) capable of reducing the emissions of waste thermal energy        and the products of combustion resulting from fuels used for        thermal heating processes at a rate defined as the renewable        energy contribution. Renewable energy contribution is derived        according to the following formula:

Renewable Energy Contribution%=(RTHR/(REFTH*THPHR−REFNTH*3413)−CompEff)*100

Where:

-   -   RTHR=the reverse thermal heat rate of the system, Btu heat        output/kWh electricity input    -   THPHR=the heat rate of thermal generating plants, Btu heat        input/kWh electricity output    -   REFTH=Fraction of generation mix provided by thermal plants    -   REFNTH=Fraction of generation mix provided by non-thermal        generation systems    -   3413=conversion from Btu to kWh or the THPHR of a 100% efficient        thermal generating plant    -   CompEff=conversion efficiency of the thermal energy system that        the system competes with Btu heat output/Btu of fuel fired.    -   (2) Thermal energy at efficiencies greater than 100% when the        efficiencies of the system reclamation are considered in        combination with the efficiency of thermal generating plants.    -   (3) Capable of generating thermal energy at a maximum efficiency        defined as the coefficient of performance of the system. This        occurs when electricity is used that is derived from a        non-thermal source, when the efficiency of a thermal generation        source reaches 100% and when the system operates in cogeneration        mode. The Coefficient of Performance is defined as the Btu of        energy output divided by the Btu of electricity input.    -   (4) Operating in cogeneration mode produces both heating and        cooling at the cost of operating the cooling system plus the        cost of operating any additional fans, pumps or controls        required to manage the heating side of the process.

Three Commercial Applications of the System

There are a vast array of applications where the Applicants' system canbe applied to take advantage of its bio-renewable characteristic and itsflexibility to operate efficiently within the three classes ofrefrigeration application. From the perspective of commercialization,there are three broadly defined markets that will benefit from thesystem. A few specific market segments are identified for each (thoughthe lists are not intended to be exhaustive).

a. Housing and commercial heating and cooling

-   -   Single Family    -   Multi-family    -   Hospitality & Dormitory    -   Offices    -   Retail    -   Warehouses/storage    -   Non-process facilities (manufacturing, assembly, laboratories,        etc.)    -   Animal confinements    -   Greenhouses and plant nurseries

b. Industrial heating and cooling

-   -   Powder coating and baked on painting operations    -   Food processing facilities (meat, dairy, baking, frozen foods,        etc.)    -   Foundries

c. Inline process

-   -   Ethanol and biodiesel processes    -   Power plants    -   Applications with both boiler and chiller or cooling tower    -   Various chemical, petroleum, drug, and agricultural byproduct        refining processes    -   Hatcheries/incubator climate control systems    -   Hay, grain or product drying processes

The new and unique feature of the system technology in these markets isits flexibility to take advantage of reclamation and cogenerationopportunities in each application. Use of the Applicants' system inplace of combustion based technologies has also been shown to provideresidual benefits in specific applications. For example, humidity can bebetter controlled to help reduce potential for disease and pests orvarious process elements can be significantly reduced such as the use offresh water for cooling an incubator. The system will also work inconcert with other energy efficient solutions, renewable energy systemsor energy storage systems to provide an additive or multiplicativeaffect. For example, a two pipe heating and cooling system in a hotel,hospital, or other commercial facility can be retrofit to include watersource heat pumps in each unit and Applicants' system that will operatebetween the boiler and the chiller to significantly reduce the rejectionmode operation of the chiller and the combustion of the boiler. TheApplicants' system will use cogeneration to take excess heat in the loopand apply it to heating potable water or the swimming pool and hot tub.If the loop needs additional heat, the system will use reclamation totake waste heat from the continuous exhaust system, waste water or otherheat sources in the facility to provide the needed heating. TheApplicants' system possesses a unique market potential in a broad rangeof applications, some of which are described in the following sections.

Thus, Applicants' system provides flexibility to utilize rejection,reclamation and cogeneration in an optimal manner to maximize energysavings and emissions reductions for a wide array of applications.Claims for specific applications are listed at the end of this patentdescription. Applicants' system can provide residual benefits such asreduction in humidity or reduction in water usage in some applicationsthat can be as valuable as the energy savings and emissions reductionbenefits.

Specific Applications and Configurations that Demonstrate the ThreeClasses of Refrigeration Application and the Bio-Renewable Energy Natureof the System

Multi-Heat Source/Multi-Heat Sink Configurations

To allow the Applicants' system to take advantage of reclamation andcogeneration opportunities it has been necessary to extend thedefinition of the system described in U.S. Pat. No. 7,040,108 to allowutilization of one or more evaporators and one or more condensers for agiven refrigeration cycle. In the most basic configuration this allowsthe Applicants' system to provide space heating, comfort cooling andpotable water heating in any facility. The configuration of theevaporators and condensers can be adjusted from application toapplication. Some applications may require only one evaporator and onecondenser. Some applications may require two or three evaporators andone or two condensers. The number and type of evaporators is determinedby the availability and type of excess, waste or ambient heat resourceand the demand for heating or cooling for the application. The numberand type of condensers is determined by the number and type of requiredheating and cooling demands of the application. The number ofevaporators and condensers associated with a given unit is also drivenby the economics of the installation and the timing of the availableheat sources and the timing of the heating and cooling demands. Whenheat resources and heating and cooling demand do not occursimultaneously, it often becomes necessary to consider thermal storageas a method of retaining heat or cool for later utilization. In someinstances the cooling demand consistently exceeds the heating demand inwhich case storage capacity for heat can be reduced by utilizing ahigher storage temperature. These concepts are developed in greaterdetail in the following descriptions relating to FIGS. 1 through 6.

Basic Heating, Cooling and Hot Water Configurations

FIGS. 1 and 2 demonstrate basic configurations of the '108 patent. FIG.2 is similar to FIG. 1, and adds the concept of using a heat exchangerand circulating pump to remove heat from the storage tank for a purposesuch as heating a space or heating a second stream. FIGS. 1 and 2 arepractical configurations for applications where there is a need forheating based on heat collected from a single ambient source or stream.These configurations were however inadequate to provide year-roundheating and cooling for a home, for example, since the heat sourcechanges from inside of the home during the comfort cooling season to theoutside for the heating season. In addition, the cooling load in acomfort cooling application often exceeds the potable water heatingrequirements so a method of rejecting the extra heat generated by thecomfort cooling process is needed.

FIG. 3 demonstrates the use of the three-way reclaim valve and thereclaim check valve to switch between the water cooled condenser and theair cooled condenser. Also illustrated is the addition of 2 two-waysolenoid valves used to supply liquid refrigerant to two evaporatorslabeled “A-Coil Evaporator” and “Evaporator”. Multiple two-way valves orthree-way valves may be used interchangeably for switching betweenmultiple condenser paths or switching between multiple evaporator pathsas the application requires. Care must be taken to provide a means toreclaim the refrigerant in a given path that is not in use, if that pathcould hold enough volume of liquid refrigerant to starve the unit whileusing other paths. This is particularly an issue for condenser paths.Without this control, when the ambient temperature around the condenserdrops, the refrigerant will tend to migrate to the condenser (condenseinside of the condenser) and starve the unit of refrigerant. Reclaim isnot as important for the evaporator paths since all evaporators are tieddirectly to the suction of the compressor. The three-way reclaim valveprovides a convenient method of reclaiming refrigerant to the suction ofthe compressor from the reclaim port on the valve. The use of normallyopen 2-way solenoid valves (if used) is also important to avoid havingthe valves fail closed and causing a deadhead situation for thecompressor. The use of the 3-way valve is again superior since it willalways have one port open and will fail open to only one port.

This configuration provides the basic components necessary to provideheating and comfort cooling to any facility (home, office, warehouse,factory, etc.) while also heating the potable water. The ability tocogenerate by heating potable water while providing comfort coolingprovides a significant advantage. If the outdoor evaporator can belocated where it can use reclamation from heated streams leaving thefacility, then the overall performance of the system can be furtherimproved during the heating season, and while heating water when thereis no cooling demand.

There are also many applications beyond simple space conditioning andpotable water heating where the second condenser (or third or fourth,etc) and the two evaporators (or third or fourth, etc.) can be placed inlocations to take advantage of specific heat sources and provide usefulheating to spaces or processes. Applying multiple evaporators andmultiple condensers in this way allows the system to be configured totake maximum advantage of reclamation and cogeneration opportunities inany application. The drive to maximize performance must be temperedrelative to the economic and residual cost/benefit of the specificconfiguration in the specific application.

Heating, Cooling and Hot Water with Multiple Heat Sinks

In some instances, an application presents an opportunity to provideuseful heating of multiple locations or processes such as the heating ofa space and the heating of a large heat sink such as a swimming pool ora process stream. U.S. Pat. No. 7,040,108 disclosed the use of one loopfor the heating of a space but did not disclose the multi-circuitpossibility. FIG. 4 demonstrates the use of more than one heatingcircuit tied to the hot water tank to allow the system to provideheating to multiple demands at or below the controlled temperature ofthe hot water tank. The desired temperature of the heat sink must be ator below the operating temperature of the Applicants' system whileoperating on a given refrigerant to allow heat transfer into the heatsink. In a housing or hospitality application, where there are swimmingpools, this configuration allows the system to reduce, if not eliminate,rejection mode operation and maximize cogeneration during comfortcooling operation or a continuous process cooling operation. A secondheating circuit is used instead of a second water cooled condenser whenthe heat demand is at a temperature significantly below the typicalrefrigerant condensing temperature (hot tank setpoint) of the system.This will allow the Applicants' system to control refrigeration systemoperation and in some instances avoid excessive frost formation on theevaporator(s) and suction piping. Each heating loop will have a solenoidvalve to control flow of water through the loop based on applicationdemand and priority. A flow control valve may also be placed in eachloop to allow the heat transfer out of the tank to be limited to theheat entering the tank from the water cooled condenser. Each loop mayhave its own circulating pump as shown in FIG. 4 or a single pump may beused to supply circulation for all loops.

Heating, Cooling and Hot Water with Wann Water Heat Sink

A slight variation of the multiple heat sink concept advanced in FIG. 4is demonstrated in FIG. 5. In this configuration, warm water is suppliedto the cold supply of plumbing fixtures throughout a facility exceptpossibly for water used for drinking, ice making and food preparationpurposes. The intent is to provide additional heating load during thecooling season to help avoid the need for rejection mode operation aswith an air cooled condenser. The system would not be used during theheating season unless it provides value to some process within anapplication. The fact that the cold water supply is heated will reducethe demand on the hot water since the mixing at the point of use will bebiased more towards the cold than usual to arrive at the same level ofcomfort for the user. There are also commercial applications such aslaundry operations, dairy cow drinking water supply and humidificationsystems for incubators where 70° F. to 90° F. water is preferred totypical ground water temperatures. Using 70° F. to 80° F. water in thetoilets and cold water piping to limit condensation and sweating canhelp reduce mold formation in walls and ceilings and reduce liabilityfor people slipping on wet floors in public restrooms. Restaurants maybe able to utilize the warm water supply to avoid rejection modeoperation of an air cooled condenser during the comfort cooling season.

There are two configurations presented in FIG. 5, cool water supply withmixing valve and cool water supply with independent tank. Both optionsreduce energy consumption by reducing the need for rejection modeoperation during a cooling process and can be used in specificapplications where warm water is desirable. The Hot Control valve isopened and Cool Control valve is closed only when the hot water tank issatisfied and the system is calling for cooling. As soon as the hot tankcalls for heating, the valves will return to their de-energizedpositions (the Hot Control valve will close and the Cool Control valvewill open).

The mixing valve configuration allows warm water to be generated ondemand helping to reduce concerns about bacterial growth in warm waterstorage tanks. This approach is best used when there is a continuousdemand for cool water since there must be a demand for cold water toprovide continued support of the comfort cooling demand. The independenttank option allows a larger supply of heated water to be stored andavailable for use and it allows the comfort cooling to be extended for alonger period of time after water usage or during periods of time whenthere is no cold water demand. An additional benefit of the tankrelative to the mixing valve is that the water supply temperature to theuser will not suddenly switch from cold to cool or from cool to coldwhen the hot and cool control valves actuate. If the temperature of thecool water tank reaches its set point, the system will either shut offthe cooling process or switch to a heat rejection mode if it isavailable until water is used allowing the system to continue togenerate hot or cool water. If a mixing valve were added to the tankconfiguration the tank could be heated to a higher temperature whilecontrolling cool water temperature at the faucet.

The cold water bypass valves in the independent tank option are used toallow the cool water tank to be used to store hot water during theheating season. Bypass valve 1 is closed and bypass valve 2 open whenthe system is calling for cooling. Bypass valve 1 is open and bypassvalve 2 is closed when the system is calling for heating. These valvesmay be manually operated valves or automated to respond to the systemthermostat. During the heating season, if the bypass valves are properlyset for bypass mode, the thermostat on the cool tank may be set to allowit to reach hot water temperatures. During the comfort cooling seasonthe thermostat on the cool tank may be set to hold the temperature tothe warmest acceptable temperature for cool water supply.

Heating, Cooling and Hot Water with Thermal Loops and Thermal Storage

The Applicants' system with its flexible configuration provides a uniquecapability to support heating and cooling operations that involvethermal fluid loops and thermal energy storage. The thermal loop orstorage system may operate to provide either cooling or heating ondemand. FIG. 6 depicts a basic thermal system with both fluid loop andthermal storage. The fluid and storage media may be water, a mixture ofglycol and water or one of any number of thermal fluids available on themarket. The storage system may also utilize phase change or phase changematerials to boost the energy density on the storage device.

The Applicants' system refrigeration cycle configuration is the same asany of the multi-heat source/multi-heat sink configurations illustratedin FIGS. 4 and 5 except this configuration explicitly utilizes a chilleras one of its evaporators. There is only one condenser shown however aspecific application may call for additional condensers. For example, asecond condenser may be used to reject heat to a cooling tower or aircooled condenser when a facility's heating demands are satisfied andthere is still need for comfort cooling. If the system is used only forcooling, the Heating Heat Exchanger, associated piping and the FluidControl valves may be omitted from the configuration. If the system isused only for heating, it will take the configuration of the systemdepicted in FIG. 4, except that now the hot water tank might involve aphase change mechanism to increase the storage capacity of the system.

The circulation loop between the water cooled condenser and the hotwater tank adds a heat exchanger in the loop rather than utilizing aseparate circulating loop. This offers the advantages of providing thehighest temperature for the heat exchange with the thermal loop/storagesystem and it avoids the operation of an additional pump. It does implyhowever, that the circulating pump must be wired to operate wheneverthere is a call for heat from either the thermal system or the waterstorage tank. It also forces the configuration of the thermal systemloop to have the Chiller Fluid Control and Heating Fluid Control valvesto avoid heating the loop during cooling operations when the system isin operation. The alternative would be to provide an independent heatcirculating loop between the hot water tank and the thermal system loopas illustrated in FIG. 4. This eliminates the need for the Chiller FluidControl and Heating Fluid Control valves and places the chillers andheating heat exchangers on the same loop, however it adds the cost ofoperating an additional pump. Both approaches will work and will beselected primarily on the basis of cost versus the effect on systemenergy efficiency. The number of pumps and the configuration of thethermal loop system will vary from application to application. Thethermal system loop may or may not include a thermal storage device(Heat/cool Fluid Tank) depending on the requirements of the application.This implies that in some instances the tank and one of the pumps in thethermal system will not exist. Backup heating and cooling may come fromany economically viable source tied into the thermal loop. In mostthermal loop systems like this today, the backup heating and coolingwould be provided by a boiler and chiller or cooling tower.

This Applicants' system configuration provides a unique opportunity toutilize reclamation and/or cogeneration to significantly improve theefficiency of existing thermal loop systems in many facilities and itoffers opportunity for a number of new applications where thermal energy(heat or cool) can be efficiently stored for later use. Consider, forexample, the two pipe heating and cooling system example discussed aboveregarding the commercial application of the Applicants' system in ahotel. The two pipe system is represented by the thermal loop systemeither with or without the tank. The tank will often be used in thisapplication since it provides a dampening affect to the loop to helpreduce the variability in loop temperature. The chiller is used incogeneration mode operation to provide cooling to the thermal loopsystem while it heats the potable water for showers and laundry or itheats a swimming pool. The Evaporator (one or more of them), operated inreclamation mode to provide heating to the thermal loop system, can belocated in various exhaust streams such as the continuous makeup airsystem exhaust, restaurant kitchen exhaust, laundry drier exhaust, orthe wastewater from the showers and laundry. The Applicants' system issized to match the typical base load heating and cooling for thefacility within the constraints of the available heat sources and heatsinks. The backup heating and cooling systems may then be sized tomakeup the difference between extreme operating conditions and thetypical operating conditions. Another sizing approach would be to sizethe system to satisfy the demands usually experienced during the springand fall and size the boiler and chiller for the remainder of the winterand summer extremes. The loop may be operated either in hot and coldmode to provide heating and cooling via a simple fan coil in each hotelroom or the loop may be operated at a given temperature such as 55 F toprovide heating and cooling via water source heat pumps in each hotelroom or temperature controlled space serviced by the loop. It would bepossible to also provide backup heating and cooling from a groundconnected heat pump system as opposed to a boiler and chiller ifsufficient ground connection capacity can be economically obtained in anenvironmentally acceptable manner at the application site. With theApplicants' system, the scale of the ground connected system can bereduced to help hold down overall implementation cost.

A good example of a system where this configuration is used for heatstorage is in a green house. The greenhouse is subject to significantsolar gain on clear days even when the outdoor temperatures are cold.This affords the opportunity to collect the excess heat during the dayand utilize it to heat the space during the night. Ideally, a phasechange material will be used in the storage tank to increase the energydensity of the storage tank and the phase change material will beselected to allow storage at the normal condensing temperature (hotwater tank set point) of the Applicants' system. An advantage ofremoving the excess heat from the greenhouse (beyond the obviousbenefits to the plants) is that the total amount of heat that might becollected will increase, since the cooler temperature in the facilitywill reduce losses to the outdoors and more solar energy will becaptured in a cooled space than in a heated space. This will be true ofany solar thermal collection system when it is coupled with Applicants'system. When the collector is cooled, it will collect more heat. Thecollected heat may be used directly by circulating the heated storedfluid and if the storage system temperature falls below a useful heatingtemperature, the system can be used to extract additional heat from thestorage tank until it reaches a temperature that will prohibitreasonably efficient operation.

Heating, Cooling, and Hot Water with Parallel Units

In some applications more than one energy reclamation unit with itsvarious components is required to satisfy the heating and/or coolingrequirement. In these applications, particularly in commercial andindustrial settings, it can be more economical to utilize onecirculation pump and/or a common hot water tank for more than one unit.The more easily controlled multi-unit configuration on the watercirculation side is a parallel configuration so that each unit willexperience the same operating conditions or water temperatures in thewater cooled condenser. Using a series configuration will causedownstream units to experience higher temperatures in the water cooledcondenser and as a result higher compressor head pressure andrefrigerant temperature. While this temperature differential could beused as a means of turning units on and off, it can be difficult tosynchronize the controls with the hot tank thermostat. Each unit willhave its own heat sources and will be controlled independently relativeto those sources. Care should be taken to try to group units withreasonably similar heat sources to allow the units to operate atrelatively similar operating conditions on the refrigerant side. Forexample, one unit may be servicing a chilled water loop at 40° F. whilethe other unit is reclaiming heat from a wastewater tank at 125° F. Thecompression ratio of the two compressors could be significantlydifferent relative to the condensing temperature which is controlled bythe temperature of the hot water tank. The unit operating on the colderenvironment may reach a compression ratio condition that exceeds therecommendation for the compressor before the hot water tank thermostatis satisfied, putting that unit in danger of failure or reducedoperating life.

A disadvantage of using common circulating pumps and common tanks for agroup of units operating in parallel is that all of the units will beout of operation if the pump, the tank or a common header experience afailure. The redundancy of using a circulating pump for each unit orsupplying a spare pump in parallel may be required in some applicationsto minimize risk or costs associated with an outage.

Summary of Benefits for Multi-Heat Source/Multi-Heat Sink Configurations

-   -   (1) The Applicants' system can utilize one or more evaporators        or one or more condensers independently to optimize utilization        of available heat sources and heat demands according to the        timing of events within a given application process. This        extends the use of one evaporator and one condenser as disclosed        in U.S. Pat. No. 7,040,108.    -   (2) The Applicants' system can be used to provide heating,        cooling, and heated water for any application.    -   (3) The Applicants' system will utilize 1 or more 3-way or 2 or        more 2-way valves and controls to switch between evaporators and        between condensers according to the priorities of the        application that are defined in the control system.    -   (4) The system can provide hydronic heat to one or more heat        sinks via a hydronic heating loop.    -   (5) The system can provide both chilled water and heated water        for a hydronic heating and cooling system.    -   (6) The system can provide tempered water in place of cold water        as a way to avoid use of an air cooled condenser during comfort        cooling season. This reduces energy consumption by avoiding fan        operation, increases heat storage capacity, and reduces sweating        from pipes and fixture.    -   (7) Units can be installed in parallel to utilize common        circulating pumps and storage tanks for increasing capacity        while reducing installation cost.    -   (8) The system can be used with phase change materials to        efficiently store heat or cold for later use in a process or        facility.    -   (9) The Applicants' system can be used with solar thermal heat        collection systems or greenhouses to maximize the thermal energy        capture because the collector is continuously cooled which        reduces losses to the surroundings and increases the amount of        thermal energy that can be collected.

Multi-Stage Heat Dissipation Configurations

The condensing path or heat dissipation side of the refrigerant cycle,can be split into useful subcomponents for the purpose of transformingenvironments or process streams from one state to a desired state. Forexample, it is possible to utilize one portion of the heat dissipationpath of the refrigeration cycle to heat a process stream while anotherpart of the dissipation path is producing steam. The refrigerant passesthrough three physical phases (vapor, vapor/liquid mixture, and liquid)during heat dissipation. The refrigeration processes associated witheach phase are desuperheating (vapor), condensing (vapor/liquid mix) andsubcooling (liquid). Desuperheating and subcooling occur over a range oftemperatures while condensing occurs at a single temperature or over asmall range of temperatures if the refrigerant is a mixture ofrefrigerants. Each process occurs at approximately the same pressure,except as affected by pressure losses in the piping and systemcomponents. In general, each segment of the heat dissipation path may beused to accomplish specific tasks and each segment may be further splitto satisfy application requirements. Because the refrigerant is goingthrough a phase change and experiencing significant variation indensity, it will be desirable to select heat exchangers that bestaccommodate the specific phase of refrigerant being processed. Forexample a heat exchanger and associated piping that handles superheatedvapor will be sized and designed differently than a heat exchanger andpiping that will process subcooled liquid and both of these may bedifferent than a heat exchanger and piping that processes a vapor/liquidmixture. The physical state of the application space or process streamsmay also pass through or be in various phases such as if water wereheated to produce steam which will further impact equipment and processdesign.

In the prior art, the water cooled condenser or external condenser ofthe system was assumed to accept or reject all of the energy associatedwith desuperheating and condensing. With multiple water cooledcondensers, two or more heated conditions can be controlled at a desiredtemperature. Little attention has been given in the prior art to theenergy of subcooling, although subcooling is a critical factor in claimsrelated to frost formation on evaporators and will be an importantconsideration for process efficiency for some refrigerants. Whensubcooling is applied, a second or third water cooled condenser(technically called a subcooler) will be required, as described in thefollowing sections. When the universal formulae and the principles ofthe classes of refrigeration are applied to an application, the bestarrangement and split of the heat dissipation path will be determined sothat the refrigeration process and the application requirements will bebalanced.

The following sections, along with FIGS. 7 through 11, describe a few ofthe basic configurations and applications where the heat dissipationpath of the refrigerant can be split to satisfy the requirements of anapplication. As with any embodiment of Applicants' system, themulti-stage heating configuration may be designed for a continuousheating process, batch heating, or both, depending on the applicationrequirements. The configurations described below extend the multi-heatsource/multi-heat sink approach disclosed above to include multiple heatexchangers in a given heat dissipation path and the ability to controloperation to heat process liquids to higher temperatures.

Heating, Cooling, and Hot Water with Mixed Superheat Cogeneration andRejection

A special refrigeration configuration has been developed forapplications where the cooling demand exceeds the heating demand but theapplication will benefit from stored thermal energy at a temperaturehigher than the normal condensing temperature (hot water tank set pointtemperature). The configuration is illustrated in FIG. 7. Theconfiguration on the refrigeration side is like other multi-heatsource/multi-heat sink configurations except that there are two 3-wayvalves on the condenser side of the compressor and those valves areconfigured and controlled in a special way. The 3-way valve C3V1supplies compressed refrigerant to the water cooled condenser or to theexternal condenser. Valve C3V1 as shown, is not a 3-way reclaim valvehowever it can be, since check valve 1 is required. Valve C3V1 allowsthe system to operate in normal water heating mode or heat rejectionmode (if the second condenser is not used for some specific heatingapplication). The second 3-way valve C3V2 is positioned down stream ofthe water cooled condenser and discharges either to the receiver or tothe external condenser. Valve C3V2 must be a 3-way reclaim valve sinceit will be used to draw refrigerant out of the external condenser whenthe water cooled condenser is being used to heat the hot water tank totemperatures below hot water tank set point (i.e. the refrigerant willbe condensing in the water cooled condenser). When both valves areenergized the system will continue to heat the hot water tank above thenormal hot water set point (normal refrigerant condensing temperature)when there is a call for additional cooling. The water cooled condenserwill operate in desuperheat mode (i.e. the refrigerant remains a vaporin the water cooled condenser and is passed to the external condenser tocomplete condensation). Thus the system provides a mixed cogenerationand rejection mode operation when used for comfort cooing and waterheating. The refrigerant leaving the water cooled condenser attemperatures above the condensing temperature is still a vapor and willthen travel to the external condenser to be condensed. It is importantthat the hot refrigerant lines between the water cooled condenser andthe external condenser are insulated to help keep the refrigerant fromcondensing in the lines before it arrives at the condenser. Preferrably,the external condenser is physically located below the water cooledcondenser so that any refrigerant that condenses to a liquid prior tothe external condenser will be carried by gravity to the externalcondenser. As with any refrigerant cycle the receiver should bepositioned below all condensers to allow the refrigerant to flow bygravity from the condensers to the receiver.

As the temperature in the hot water tank increases, the temperature ofthe refrigerant vapor traveling to the external condenser will increase.As these temperatures increase, the amount of energy captured in thewater will decrease. For many refrigerants the amount of heat capturedin the water will range from 10% to 20% of the amount that would becaptured while operating the hot water tank at or below the refrigerantcondensing temperature (i.e. 10% to 20% of normal cogeneration capacityand 80% to 90% rejection). However, the amount of thermal energy storedin the hot water tank will be greater than it could have been if thesystem were simply switched to rejection mode when the hot water tankreached its normal set point or the maximum condensing temperature ofthe refrigerant. Because the tank temperature is higher than thecondensing temperature of the refrigerant, the system cannot revert tosimple water heating mode until the temperature in the tank is reducedto the condensing temperature of the refrigerant.

This configuration is ideal for any facility with a high cooling loadthat can use a limited amount of higher temperature water. One exampleis a carwash that is co-located with a restaurant. The cooling demand ina restaurant (particularly from the kitchen) will coincide with mealtimes, while the heating demand for the car wash will coincide with thecar wash cycle which will usually be greatest after work hours onweekdays and all day on weekends. The heat rejected from the kitchenwill be stored in the hot tank at the highest temperature permissiblefor the installed equipment and the water going to the car wash from thehot tank will be tempered down to acceptable conditions for use in thecarwash by use of a mixing valve. At the point where the car wash demandreduces the hot tank temperature to the normal set point temperature,the system will revert to normal water heating mode to eliminate therejection mode operation of the external condenser and maximize heatcapture into the water.

The above examples assume that the external condenser operates to rejectheat. It is not necessary that this condenser be used solely forrejection. For example, a combination dry cleaner/laundry with a smalllaundry load could use this configuration to provide comfort cooling forthe dry cleaning process while generating water at 80° F., 125° F., and180° F. The 125° F. water would be generated using only the water cooledcondenser while the 80° F. and 180° F. water would be generated usingboth the water cooled condenser and the external condenser, which inthis case would be another water cooled condenser. Thus the externalcondenser would be used to heat incoming cold water to 80° F., which isa luxury that adds value to the laundry process but is usually notaffordable when heating water with a fuel. The heat rejection goes to auseful heating process that is optional.

Use of this configuration must be weighed against use of larger storageat normal condensing temperature and the improved efficiency affordedthrough reduced rejection mode operation given the larger storagecapacity. One of the following configurations may also provide a moreeffective solution for some applications.

Heating, Cooling, and Hot Water with Superheated Liquid

In some applications it is of value to incorporate two or more water orliquid cooled condensers in series to achieve one or more objectives aswas identified in the dry cleaner/laundry example described in theprevious section. These condensers may provide desuperheating,condensing or subcooling to the refrigerant while heating the liquid todesired conditions or providing stable, efficient refrigeration systemoperation.

A two water cooled condenser configuration shown in FIG. 8 is similar toFIG. 7 except it includes the second water cooled condenser WCC2 and itsown circulating loop and storage tank in addition to the externalcondenser EC. This system is capable of producing two temperatures ofwater or liquid, mixed cogeneration/rejection mode operation asdescribed in the previous section and rejection of heat via the externalcondenser. The first water cooled condenser WCC1 is used for generatingwater or liquid at temperatures greater than the normal condensingtemperature of the refrigerant. It will operate in condensing mode untilthe temperature of the water in its circulating loop exceeds thecondensing temperature of the refrigerant. At that point WCC1 willhandle superheated refrigerant vapor and is capable of heating the waterin its circulating loop and storage tank to a temperature thatapproaches the temperature of the superheated vapor entering WCC1.Tanks, pumps, valves, piping, insulation, etc. associated with this loopmust all be selected to withstand the temperatures that are desired orpossible with superheat operation. Testing with R22 in a 5-tonreciprocating compressor has yielded water temperatures in theneighborhood of 200° F. in batch mode operation. The refrigerant vaporentering WCC1 can be in the range of 220° F. to 260° F. This impliesthat it would be possible to generate steam at atmospheric and lowpressure conditions using R22. This was verified in testing, as a fewtimes the system vapor-locked due to steam formation in WCC1. Adifferent heat exchanger and piping arrangement would have been neededto separate the steam and water for a steam production process.

WCC2 is used to heat water or liquid in its circulation loop up to themaximum condensing temperature of the refrigerant as controlled by thethermostat in WCC2's hot water tank. This water can be supplied eitherto WCC1's circulation loop or to a hot water supply system for theapplication. When using a system like this it is good to have a use fora hot liquid at the condensing temperature provided by WCC2 and at ahigher temperature provided by WCC 1. When WCC1 is in desuperheatingmode on an R22 system, 80% to 90% of the available heat will come outthrough WCC2 while 10% to 20% will come out through WCC1. Thesepercentages will vary with the refrigerant used in the system.

Cold water is introduced into the WCC2 loop on the suction side of thecirculating pump to take advantage of tempering. If the system iscontrolled to produce a continuous flow at a specific temperature, thecold water will mix with the heated water entering WCC2. This can allowthe tank in the WCC2 loop to operate at 5° F. to 8° F. higher than thenormally acceptable condensing temperature of the refrigerant, since thecompressor will see a head pressure corresponding with the mixed watertemperature rather than the temperature of the water in the tank. Theflow in WCC2's circulating loop is controlled using the Hot Circ FlowControl valve and the tempering water flow rate can be controlled by theTempering Flow Control valve. These flow rates can be adjusted to obtainthe desired level of temperature control. This tempering affect is ofcourse only available if there is a continuous flow of water through thesystem. Similarly, hot water leaving the WCC2 tank is routed to thesuction side of WCC1's circulating pump. This allows the desuperheatingprocess to see a lower temperature at the water side inlet to WCC1,which increases the amount of heat transfer that can be obtained for agiven temperature in WCC1's tank. The HT Supply Flow Control valve isused to control the flow of water to allow the system to maintain a setpoint temperature leaving the tank. If there was no Hot Supply line(i.e. the system heats water on a once through basis) then the HT SupplyFlow Control valve could also provide the same affect as the TemperingFlow Control valve for WCC2's circulation loop. The number, style andlocation of flow control valves will vary with the requirements oropportunities of an application. For example, if the Hot Supply and HTSupply are exposed to atmospheric pressure, then the flow control valveswill be best located in the Hot Supply and HT Supply lines. Anotherexample is where a 3-way proportional control valve can be located inthe circulation line between the tank and the tempering supply. The3-way valve would discharge water at a rate sufficient to allow thetemperature in the tank to be held relatively constant. The priority inany combination of flow control valves will be to ensure that thecompressor head pressure is controlled to within acceptable limits whilemeeting the temperature requirements of the application. There is noneed to limit the circulation flow rate in WCC1's circulation loopalthough it could help to impose a temperature differential across thewater side of WCC1 to promote better heat transfer.

Theoretical analysis shows that given the right evaporator conditionsand proper equipment selection while using existing refrigerants, therefrigerant condensing temperature (WCC2) can be maintained as high as150° F. The greatest limitation on the use of this configuration is thetemperature of the superheated refrigerant vapor, or more importantly,the temperature of the oil in the superheated vapor entering WCC1. Thistemperature must remain below the point where the oil begins to breakdown and lose its lubricating capability. The choice of refrigerant andthe efficiency of the compressor can have a significant impact on thistemperature. With proper equipment selection the configuration can beused to produce saturated steam at low pressures. An additional heatexchanger of appropriate design would be needed to generate superheatedsteam.

Hydronic heating loops can be applied to either tank. The return from ahydronic loop originating in the WCC1 tank may return either to the sametank or to the WCC2 tank. The primary factor in determining which tankit will return to is the temperature of the return relative to thetemperature of the tanks. If the return is hotter than the temperaturein the WCC2 tank it must be returned to the WCC1 tank, the return from ahydronic heating loop originating from the WCC2 loop must return to theWCC2 tank.

The utilization of this configuration, to produce a liquid or vapor at atemperature higher than the nominal refrigerant condensing temperature,will be useful in any application where there is a need for cleaning orsterilization of clothing, and equipment such as in laundry,agricultural, food processing, and medical sectors. For example, ahatchery has a significant cooling load to keep the eggs from overheating. The hatchery also needs to sterilize the equipment used to holdthe eggs and the chicks several times a week. This configuration can beused to generate and store high temperature water for use in the washwhile maintaining the cooling for the eggs.

Heating, Cooling, and Hot Water with Subcooled Liquid

FIG. 9 is the same as FIG. 8 except it utilizes the configuration verydifferently. The objective of this utilization is to provide heatedliquid at the condensing temperature in WCC1 and warmed water fromsubcooling in WCC2. The circulating loop for WCC2 is used to maintain anaverage temperature in the tank for subcooling. This is useful if thewater usage through the system is intermittent or the temperature ofwater returned from hydronic heating loops is variable. The tank helpsto keep the refrigeration system operation more stable. If theconditions of the cool liquid entering WCC2 will be consistent such asmight be the case with a once through heating system, the circulatingloop and tank may not be necessary as depicted in FIG. 10. In this case,the warmed water is introduced directly into the suction side of theWCC1 circulating loop pump. There may be applications where warmed wateror liquid can be useful.

This configuration will be important for use of refrigerants such asR410A and R422B. The added subcooling is important for obtaining themaximum efficiency out of the refrigeration cycle. When the refrigerantis expanded through the TX valve, a certain fraction of the refrigerantis converted to a vapor and the rest remains a liquid. The expansionprocess is considered to be isenthalpic or it occurs at a constantenthalpy. Enthalpy is the measure of the energy content of therefrigerant in Btu/lb. The enthalpy of the liquid refrigerant leavingcondenser WCC2 will be greater than the enthalpy of the liquid leavingWCC2, since some energy will have been imparted to the water or liquid.This subcooling will allow the fraction of vapor in the mixture to belower and the fraction of liquid in the mix to be higher after the TXvalve. Since the refrigeration effect is produced by the boiling of theremaining liquid fraction of the liquid/vapor mixture in the evaporator,the mixture generated from the subcooled refrigerant will be able tocapture more heat in the evaporator. When the evaporator captures moreheat, the refrigeration effect is increased and the COP of the system isenhanced. The maximum refrigeration effect occurs when the liquidrefrigerant is subcooled to the temperature which corresponds tosaturated liquid at the suction pressure or pressure at the inlet of theevaporator. For some refrigerants such as R410a and R422B the system canlose in the neighborhood of 40% to 50% of the refrigeration effectduring expansion in the TX valve. By using subcooling, the refrigerationeffect and system efficiency will be significantly increased.

This utilization of this configuration can be applied anywhere that thesystem can be used with consideration of the issues related to usingonce through subcooling as in FIG. 10 or using a tank and circulatingloop as depicted in FIG. 9. To take advantage of the subcooling, thesystem is best applied in situations where there will be a consistentflow of water or liquid to be heated or in the case of a hydronicheating system to be reheated.

Heating, Cooling, and Hot Water with Superheated Liquid and Subcooling

FIG. 11 illustrates a system configured to provide subcooling via WCC3,condensing via WCC2 and superheating via WCC1. The configurationbasically combines the concepts of the previous 2 sections to arrive ata way of generating higher liquid temperatures while maintaining higherefficiency through use of subcooling. The same concepts of superheat andsubcooling apply except they are combined into the same system. A fourthheat exchanger would be needed prior to WCC1 in the refrigeration pathif the system were to be used to generate superheated steam.

When multiple heat exchangers are connected in series, the designer mustbe careful to size the equipment to control the pressure drop on bothsides of the heat exchangers or water cooled condensers. The pressuredrop on the refrigerant side should be held to a minimum to help limitcompressor power requirements and maximize capacity. The pressures andpressure drops on the water or liquid side should be controlled to avoidcreating low pressure points where heated liquid may become prone toboiling where it isn't desirable. If boiling occurs, the system will besubject to vapor locks and cavitation in water pumps.

Summary of Multi-Stage Heat Dissipation Benefits:

-   -   (1) The ability to use two heat exchangers (referred to as a        water cooled condensers WCC1 and WCC2) in series in the        refrigerant path to provide heating of water or a liquid to        temperatures higher than the normal maximum condensing        temperature of the refrigerant at the head pressure of the        system. WCC1 desuperheats the refrigerant while WCC2 condenses        the refrigerant.    -   (2) The ability to use two heat exchangers in series in the        refrigerant heat dissipation path to provide subcooling of the        refrigerant to improve system refrigeration and heating effect,        overall system capacity and coefficient of performance. WCC1        desuperheats and condenses the refrigerant and WCC2 subcools the        refrigerant.    -   (3) The ability to use three heat exchangers in series in the        refrigerant heat dissipation path to provide both subcooling of        the refrigerant and heating of water or a liquid to temperatures        greater than the normal maximum condensing temperature of the        refrigerant. This provides improved performance as well as        improved system flexibility and increased application        opportunities. WCC1 desuperheats the refrigerant, WCC2 condenses        the refrigerant, WCC3 subcools the refrigerant.    -   (4) The ability to apply any refrigerant to the claims of this        section with allowance for equipment needed to accommodate        specific properties of the refrigeration that may not have been        specifically identified in this description. For example, the        equipment used to refrigerant R410A must be capable of handling        the higher pressures required for operation using R410A.    -   (5) The ability to use any reasonable number of heat exchangers        in series in the refrigerant heat dissipation path to achieve a        goal of heating one or more liquids to desired conditions.    -   (6) The ability to use any reasonable number of the appropriate        heat exchangers in series in the refrigerant heat dissipation        path to boil water or other liquid being heated.    -   (7) The ability to use a thermostatically controlled tank and        circulation pump with each heat exchanger in series to provide        heated liquid storage and consistent or controlled process        temperatures.    -   (8) The ability to generate heated water in batch or on a        continuous basis. For continuous flow the ability to apply any        variety of water flow control regimes to provide compressor head        pressure control or subcooling control while obtaining the        desired quantities of water heated at the desired temperature.        Flow controls may include but will not be limited to manually        operated valves or any of a variety of automated valves operated        to vary the flow so as to maintain the desired temperature of a        given circulating loop and storage system.    -   (9) The ability to control the temperature of liquid refrigerant        leaving the last heat exchanger in the refrigerant heat        dissipation path through use of the thermostatically controlled        tank and circulating pump at a temperature which improves the        refrigeration system performance by helping to control ice on        the evaporator and allowing the compressor to operate at a more        efficient operating point.    -   (10) The ability to apply multiple sets or circuits of series        heat exchangers in parallel from the same compressor using 3-way        or 2-way valves to take advantage of different operational        opportunities in an application.    -   (11) The ability to apply a condenser for use in rejecting heat        in parallel to a series of heat exchangers in the refrigerant        heat dissipation path.    -   (12) The ability to heat a liquid to temperatures higher than        the normal refrigerant condensing temperature using a fraction        of the available heat while rejecting the rest of the heat or        using it in an optional heating process.    -   (13) The ability to define a refrigeration system that uses two        or more 3-way or 2-way powered valves to control the        refrigeration process according to thermostats associated with        various states or operating modes of an application. For        example, the 7 controllable components of the system illustrated        in FIG. 8 are tabulated with the 6 operating modes of the system        in the green table on the exhibit drawing. Operating modes        include use of two different evaporators to collect heat to heat        either the hot tank (WCC2) or the high temperature tank (WCC1).        Also included is a mode for mixed cogeneration to the high        temperature tank and rejection via the external condenser EC and        a mode for pure heat rejection operation using the external        condenser EC.    -   (14) The ability to apply multiple compressors each with        multiple heat exchangers in series in the refrigerant heat        dissipation path in a parallel configuration with the        circulation and tank system. In-other-words the circulation        pump, tank and associated hydronic heating systems may be shared        across multiple RASERS units each with their own evaporators and        heat sources.    -   (15) The ability to conduct refrigerant subcooling via a direct        water (liquid) source or returns from a hydronic heating system        where the mixture of water (liquid) entering the subcooler will        be relatively consistent in volume and temperature, (FIG. 10).    -   (16) The ability to conduct refrigerant subcooling via a        circulating system with a tank to help stabilize the operation        of the refrigeration system when the supply and return water are        variable (Figure).    -   (17) The ability to heat water, glycol, oils, ethanol, or any        liquid in the liquid cooled heat exchangers provided the heat        exchangers are selected with respect to the properties of the        liquid.    -   (18) The ability to heat air or any gas or vapor in the heat        exchangers provided the heat exchangers are selected with        respect to the properties of the gas or vapor.

Multi-Stage Heat Collection Configurations

The Applicants' system may utilize any evaporator or evaporatorconfiguration that satisfies the requirements of the refrigeration cyclewhile serving the demands of the application. This patent previouslydescribed the use of more than one evaporator circuit to allow thermalenergy to be collected from different locations where only oneevaporator circuit was used at a time. In this section we expand thedefinition of a circuit to include use of one or more evaporators in acircuit at the same time as dictated by the requirements oropportunities of the application. Some applications may require multipleevaporators in series and some may require multiple evaporators inparallel for a given mode of operation. In general, the evaporatorcircuit may be split into more than one evaporator when the applicationprovides multiple heat sources that are smaller than the nominalcapacity of the Applicants' system selected to satisfy the thermalenergy demands of the application.

The basic parallel configuration includes the use of an expansionconfiguration at each evaporator. The high pressure liquid refrigerantleaving the receiver may pass through a set of valves (2-way or 3-way)to select the desired evaporator circuit based on environmentalvariables. After the valves, the refrigerant is split through use oftees or a distribution device to supply each parallel evaporator path inthe circuit. It is important that the splitting process be designed soas to avoid expansion of the refrigerant until it reaches the expansionconfiguration. After the split the liquid refrigerant will pass throughthe expansion configuration (TX valve, orifice, distributor, etc.) onits way to the evaporators. After the evaporators the superheatedrefrigerant will be recombined into the suction line feeding thecompressor using tees or other means to collect multiple refrigerantstreams into one. With parallel evaporators it may be necessary toutilize a pressure control device between the evaporators and thecompressor to ensure that the pressure leaving the evaporators is thesame. An example where parallel evaporators can be used is in a hogbarn. Two or more evaporators may be placed in front of separate exhaustfans to allow thermal energy capture sufficient to allow the unit tooperate at nominal capacity.

The basic series configuration uses only one expansion configuration butsplits the evaporator into two or more parts to provide the coolingeffect to two or more environments while satisfying the superheatingrequirements of the refrigeration cycle. The multiple evaporators willusually be reasonably close to each other and the pipe connecting theevaporators will usually be well insulated to avoid losing therefrigeration effect between the evaporators. The refrigerant may passbetween the evaporators through a single pipe or it may pass throughmultiple pipes or a multi-port mixing device. An example where a seriesconfiguration is useful is where an environment may require a small orcontrolled amount of cooling relative to the total cooling capacity. Theevaporators will be sized to support the controlled cooling activity andmay be made from any material as dictated by the environment served bythe evaporator.

The temperature of the refrigerant during evaporation (a liquid/vapormixture) will be constant or for a refrigerant mixture, will vary by asmall amount while the refrigerant is boiling within the evaporator(i.e. just like water boils at 212° F. at standard atmosphericpressure). After all of the refrigerant is boiled, its temperature willbegin to rise as more thermal energy is applied to the evaporator (thisis called superheat). The temperature rise (degrees of superheat) islimited to only the amount necessary to avoid introducing liquidrefrigerant into the compressor. It is also beneficial to limit theamount of superheat because the capacity of the compressor decreases asthe amount of superheat increases due to the reduction in density of thesuperheated vapor as its temperature increases. The thermal expansion(TX) valve usually provides a means to adjust the degrees of superheat.The expansion and evaporator configuration must be selected to providethe best possible system capacity while satisfying the cooling demandsof the environments served.

The evaporators must be selected to account for differences in theenvironmental conditions. For example if two evaporators operating inseries experience different environmental temperatures then theevaporators may or may not be the same size depending on how much of theevaporation process each evaporator is intended to handle. In contrasttwo evaporators operating in parallel will likely be sized differentlyif they are exposed to different temperature environments to help matchthe temperature and pressure of the refrigerant leaving each evaporator.Parallel and series evaporator configurations are most easily applied tomultiple similar environments. Series evaporator configurations can bemore easily applied to multiple environments with different operatingconditions or multiple environments with similar operating conditions.

Summary of Multi-Stage Heat Collection Claims

-   -   1. Ability to use one or more evaporators in an evaporator        circuit.    -   2. Ability to connect multiple evaporators in series or in        parallel on a single circuit.    -   3. Ability to use one or more evaporators to provide multiple        controlled cooling activities for air, water, glycol mixtures,        oils, ethanol or any liquid, vapor, or gas to be cooled.    -   4. Ability to use multiple elements in the expansion        configuration such as the TX valve, orifice, and distributor.    -   5. Ability to use evaporators manufactured from any material        (copper, stainless steel, aluminum, etc.) as dictated by the        environment served by the evaporator to protect the evaporator        from failure due to corrosion, erosion, thermal fatigue, or        other phenomenon.    -   6. Ability to size evaporators to match different environmental        conditions while obtaining desired refrigeration system        operation.

Summary of Exemplary Uses of the System

Laundromat—In a laundromat, the system heats fresh water for a washcycle while providing comfort cooling for the workers/customers, bycollecting waste heat from the drier exhaust vents, or collecting wasteheat from the waste water.Dry cleaner/Laundromat combination—The system heats fresh water ortempered water from dry cleaner cooling system while providing comfortcooling for workers/customers, collecting waste heat from the drierexhausts, or collecting waste heat from the waste water.District heating—The system utilizes the excess thermal energy from alaundromat, dry cleaner, or other energy intensive business located in acommercial or residential area to heat water that can be piped andmetered to neighboring businesses or residents for direct use as heatedwater and for use in space or process heating.Meat Processing (kill and products)—The meat processing processgenerally requires a significant amount of heated water for washing andsterilization. The system has the ability to heat water from severalsources: waste heat from the singe process, excess ambient heat from thesterilization or cooking processes (comfort cooling), waste heat fromthe carcass wash and facility cleanup wastewater, and heat expelled fromthe refrigeration processes required to chill the carcass prior tocutting or after processing. The ability to provide comfort coolingthrough use of a forced draft air handler with a-coil provided theenvironment does not present a high fouling potential. Finlessevaporators may be used to recover waste heat from singe and waste waterto minimize fouling and allow ease of cleanup. There is also the abilityto collect heat expelled by the refrigeration process using anevaporator at the exhaust of the condenser. The system has the abilityto directly provide refrigeration and water heating simultaneously. Thisis the most economical heat recovery mode since both activities areperformed using the same kW of power that was going to be used forrefrigeration regardless of how the water was heated.Car Wash—The system heats wash water for a car wash and in floor heatedwater loops used for office heating and eliminates ice formation at theapproaches to the wash bays. The heat derives from several heat sources:wastewater, excess heat in the office or mechanical room, excess heatfrom an adjoining convenience store or restaurant, warm humid airexhausted from the wash bays or the outdoor ambient air.Restaurant—A restaurant benefits from both heating and cooling affectsof the system. The kitchen is cooled year-round while water is heatedfor dish washing and for use in heating the restaurant. The restaurantcan be cooled during high occupancy and during the cooling season whileheating water for dish washing. Since the cooling load usually exceedsthe water heating demand an air cooled condenser, warm water supply, ordistrict water heating system will be needed during the summer.Swimming pool—The system can heat swimming pool water using heat fromthe ambient air or from excess heat in the offices, shower house ormechanical room (comfort cooling).Campground shower house—Shower house water can be heated with the systemusing heat from the ambient air or from excess heat and humidity in theshower house or mechanical room (comfort cooling). Comfort cooling inthe shower house may help to extend the life of equipment and parts thatare subject to the high humidity usually found within the shower house.Animal Confinement—(Animals and foul including but not limited to: hogs,dairy cattle, beef cattle, chickens, turkeys, etc.) The system has theability to heat the living space using the waste heat that is exhaustedvia the ventilation system or from comfort cooling in critical areassuch as the breeding room or boar stud area. Heating may be in the formof heating the air in the room or localized heating as for baby pigs ina farrowing crate or small animals for the first few days or weeks afterthey are weaned or hatched. Some animals may also benefit from theability to heat drinking water using waste heat from an exhaust or heatcaptured from comfort cooling processes. Some stages of animal husbandrywill benefit extensively (weight gain, survival, conception rates,reduced stress/susceptibility to disease . . . ) by providing comfortcooling during hot humid summer days. Excess heat from comfort coolingis generally used for heating wash water or drinking water or isexpelled in an air cooled condenser. If animal confinements can beproperly co-located, the system has the ability to use excess heatgenerated by larger animals to heat spaces for smaller animals. Heatingspaces using Applicant's hydronic heating system has the ability toreduce humidity and toxic gas loadings in the space when comparedagainst direct fired propane or gas heaters. The system has the abilityto use excess heat from animal confinements (heat and humidity generatedby the animals) to heat anaerobic digesters year-round. The system canalso provide the ability to transform the waste thermal energy to heatthe residence, shop/office or to provide some heat input for lowtemperature grain drying either in the bin or in a drying process via anappropriate district heating system. In some specialized animal researchfacilities, the system has the ability to heat water for thesterilization processes using waste heat from ventilation exhaust, wasteheat in the wastewater, and excess heat in the rooms where thesterilization equipment resides (comfort cooling for the workers).Dairy—The dairy farm provides a unique opportunity. The system providescooling for the milk and can be used to cool the offices, and milkingparlor. A cooled parlor may contribute to comfort for the cows andincrease milk volume. The captured heat can be used to heat Clean InPlace (CIP) water and the drinking water. Warm drinking water may alsohelp increase the amount of water the cows drink which can contribute toincreased milk production. Since dairy manure is well suited fordigesters, the excess heat from the various value added coolingactivities can also be used to support an onsite digester.In-Line Processes (General)—The in-line process involves the integrationof the system into a process to utilize the simultaneous cooling andheating affects. Most in-line processes will use cogeneration on acontinuous basis when the process is operating. The introduction of thesystem will displace a portion if not the entire use of separate heatsources and cooling sources. Any manufacturing process that needs bothheating and cooling presents an opportunity to apply the system.Hatchery—The system also has the ability to collect heat from coolingwater used to cool the incubators and from ventilation exhaust. Thereclaimed heat can be used for space heating and to heat wash water andhumidification spray water. The ability to recycle the cooling waterwill provide significant savings in water and wastewater disposal costs.The ability to integrate the system into the incubators will provideboth heating and cooling inside the box through finned hydronic systems.Anaerobic Digesters—Anaerobic digesters require close monitoring oftemperature to ensure bacterial activity. The manure must be heated asit enters the digester and the temperature must be maintained throughoutthe anaerobic conversion process. Our system provides the ability tocollect heat from the manure leaving the digester and use it to preheatthe manure entering the digester. In addition the gas treatment systemsand energy conversion systems often associated with digesters produceexcess heat which can be captured and used to preheat manure andmaintain the temperature of the manure in the digester. Waste heat fromnearby animal confinements can also be captured and used as well as heatfrom the ambient air.Bio-diesel Production—Bio-diesel production requires that the raw oil beheated and that the various process streams be heated and cooled atvarious points along the way. Most processes use a boiler to heat theoil and a cooling tower to help cool the process stream. Many processesalso use a chiller at some point in the process. The chiller can bereplaced with Applicants' stem to provide both chilling and processheating. In addition, the heat remaining in the bio-diesel afterconversion may be extracted for process use. Heat in the cooling watergoing to the cooling tower can also be used to heat makeup or condensatewater for the boiler or for heating a process stream. Excess heat in theboiler/mechanical room (includes waste heat generated by compressors)and waste heat from the boiler exhaust can also be captured andintroduced into the process. Before the bio-diesel process, the oil isusually generated in an extrusion process. Extrusion generates a gooddeal of heat which might also be captured and reintroduced into theprocess at an appropriate location.Ethanol Production—Ethanol production has some similarities tobio-diesel processing. The process involves a boiler and a cooling towerand may involve a chiller. The process streams are heated and cooled forthe various stages of the process. Some ethanol processes utilize agreat deal of fresh water to wet and cook the mash and makeup water forboiler. All of this water must be heated. The present invention can heatthe water used for the cook process and preheat the condensate andmakeup water for the boiler. Heat may be collected from the coolingwater lines either before or after the cooling processes. In a retrofitapplication, the system can help to compensate for an undersized coolingtower. Excess heat from the boiler/mechanical room and boiler exhaustare also available for heating. It may also be possible to design acondensing system to cool the exhaust from the distiller's grain driers.In addition to recycling the heat, the condensed water can also betreated and reused in the process. Seasonal applications such as spaceheating or comfort cooling may also be incorporated into the planthowever the payback on a season application is longer than the paybackfrom supporting the process.Canned or frozen vegetable or prepared food processing—The canned foodprocess usually requires cooking and elevated temperatures to vacuumseal containers. The excess and waste heat from the process can berecycled into heated process and wash water using the system. The frozenfood process usually requires chilling and may involve cooking orblanching. The excess or waste heat from these processes can be used toheat process or wash water. With our system the chilling process canperform both chilling and water heating. Excess heat can also be used toheat other parts of the facility or for a district heating system.Painting processes—Powder coat and baked paint processes utilize ovensto cure the paint and produce a great deal of excess and waste heat. Thesystem can utilize this excess thermal energy to heat wash water, heatother parts of the manufacturing facility or heat water for a districtheating system.Extrusion and molding processes—Extrusion processes generate a greatdeal of excess heat which can be utilized to heat other parts of thefacility or to heat process and wash water. Some molding processes suchas foam pallet forming utilize a great deal of heated water/steam andgenerate a large sensible and latent heat load in the facility. Thissystem can cool the facility and the cooling water while generatingpreheated water going into the boiler.Boilers and Mechanical Rooms—Boiler and mechanical rooms provideopportunity to collect excess or waste heat and heat water. Air andrefrigeration compressors generate appreciable amounts of heat andboilers have ambient radiation and convection losses as well as exhaust.Other types of equipment also generate heat. Our system will benefitcompressors by cooling the air and the environment around thecompressor. Cooler air will increase the density of the air and improvethe capacity of the compressor and cooler operating conditions willreduce wear on the equipment and lubricating oils resulting fromexcessive heat. For boilers, the excess or waste heat can be reclaimedby the system to preheat makeup or condensate return water or to preheatcombustion air. The scale of such systems can range from a few thousandBtu/hr to large utility scale power plants. Extracting heat from aboiler exhaust will require special evaporator configurations and use ofmaterials such as stainless steel that will be suitable for thepotentially corrosive boiler exhaust.Greenhouse—A greenhouse provides a significant source of heat during theday. Even on sunny cold winter days the temperature in the greenhousecan climb and produce warmer temperatures than desired. During summermonths the temperatures in a greenhouse become oppressive. This heatsource can be utilized in a number of settings. In an actual functionalgreenhouse the excess heat generated during the day can be captured bythe system and stored in heated water and then distributed into thefacility at night. During the summer when excess heat prohibits plantculture the excess heat might be used to heat water for nearbyprocesses. The greenhouse can also be used in commercial officebuildings, apartments, hotels, concrete plants, hospitals or anybuilding requiring heat that doesn't have a waste heat source. Thegreenhouse can be used to collect ventilation exhaust and solar heatgain (not necessarily used for growing plants). The heat captured fromthe greenhouse by the system can be used to heat water for showers,laundry, swimming pools, concrete mix on cold days, etc. By cooling thespace the amount of thermal energy that can be captured will increase.The moisture in a building exhaust that is captured in the greenhousecan be collected and reused for non-potable uses or treated for potableuse.High Rise Buildings, Apartments and Hotels—The system can tie into largeheating cooling and water heating systems for large high rise buildings.Using a hydronic loop and localized water heat pump/fan units heatingand cooling can be accomplished in different parts of the buildingsimultaneously by collecting excess solar gain from the sunny side ofthe building and transferring it to the shaded side of the building. Oursystem is used to chill the loop during the summer and the excess heatis used to heat potable water for showers/baths, laundry, swimmingpools, etc., and can also be used to recoup heat from continuousventilation exhaust and wastewater to makeup heat into the hydronicheating loop and to heat other spaces such as the parking garage, makeupair, etc. during the heating season.Grain and Hay Drying—Heat from warm moist air exhausted from the dryingprocess can be reclaimed by the system to preheat incoming dry air andimprove the drying process efficiency.Hydrocarbon to oil systems—Recently a number of systems are beingdeveloped for converting wet hydrocarbon materials to crude oil througha process involving high pressure and temperature (hydrothermaldepolymerization). The system can be integrated into the process topreheat the hydrocarbon-water slurry based on heat collected from thedischarged oil and heat losses from the process.

1. A bio-renewable thermal energy system comprising: a refrigerationsystem having a first evaporator, a compressor, and a first condenserwhich are operable in rejection, reclamation and cogeneration modes. 2.The thermal energy system of claim 1 further comprising a secondevaporator operated independently of the first evaporator.
 3. Thethermal energy system of claim 2 further comprising a second condenseroperated independently of the first condenser.
 4. The thermal energysystem of claim 1 wherein the refrigeration system is operable for bothheating and cooling.
 5. The thermal energy system of claim 1 furthercomprising a hydronic heating loop.
 6. The thermal energy system ofclaim 1 wherein the refrigeration system can provide both heated andchilled liquid or gas.
 7. The thermal energy system of claim 1 whereinthe refrigeration system utilizes environmental thermal energy from onesource to heat another body of fluid or air.
 8. The thermal energysystem of claim 7 wherein the one source is a meat processing plant. 9.The thermal energy system of claim 7 wherein the one source is a carwash.
 10. The thermal energy system of claim 7 wherein the one source isa restaurant.
 11. The thermal energy system of claim 7 wherein the onesource is an ethanol plant.
 12. A thermal energy system of claim 7wherein the one source is a laundromat.
 13. A thermal energy system ofclaim 7 wherein the one source is a dry cleaner.
 14. A thermal energysystem of claim 7 wherein the one source is a swimming pool.
 15. Athermal energy system of claim 7 wherein the one source is a showerhouse.
 16. A thermal energy system of claim 7 wherein the one source isan animal confinement building.
 17. A thermal energy system of claim 7wherein the one source is a dairy.
 18. A thermal energy system of claim7 wherein the one source is an in-line process.
 19. A thermal energysystem of claim 7 wherein the one source is a hatchery.
 20. A thermalenergy system of claim 7 wherein the one source is an anaerobicdigester.
 21. A thermal energy system of claim 7 wherein the one sourceis a bio-diesel production facility.
 22. A thermal energy system ofclaim 7 wherein the one source is a food processing facility.
 23. Athermal energy system of claim 7 wherein the one source is a paintcoating facility.
 24. A thermal energy system of claim 7 wherein the onesource is an extrusion processing facility.
 25. A thermal energy systemof claim 7 wherein the one source is a molding process.
 26. A thermalenergy system of claim 7 wherein the one source is a boiler.
 27. Athermal energy system of claim 7 wherein the one source is a greenhouse.28. A thermal energy system of claim 7 wherein the one source is a humanliving facility.
 29. A thermal energy system of claim 7 wherein the onesource is a grain drying facility.
 30. A thermal energy system of claim7 wherein the one source is a hydrocarbon to oil processor.
 31. Animproved thermal energy utilization process having a refrigerationsystem with a hot side and a cold side, the improvement comprising:splitting heat from the hot side for use in multiple heatingapplications.
 32. The improved process of claim 31 further comprisingsplitting the cold side for use in multiple cooling applications. 33.The improved process of claim 31 wherein the process utilizes arefrigerant having a condensing temperature, and wherein one of theheating applications is heating liquid to a temperature greater than thecondensing temperature of the refrigerant.
 34. The improved process ofclaim 31 wherein one of the heating applications is the boiling of aliquid.
 35. The improved process of claim 31 wherein the split heat isdirected through multiple heat exchangers.
 36. The improved process ofclaim 31 further comprising utilizing environmental thermal energy fromone source to heat another body of fluid or air.
 37. The improvedprocess of claim 36 wherein the one source is selected from a groupconsisting of a meat processing plant, a car wash, a restaurant, anethanol plant, a laundromat, a dry cleaner, a swimming pool, a showerhouse, an animal confinement building, a dairy, an in-line process, ahatchery, an anaerobic digester, a bio-diesel production facility, afood processing facility, a paint coating facility, an extrusionprocessing facility, a molding process, a boiler, a greenhouse, a humanliving facility, a grain drying facility and a hydrocarbon to oilprocessor.
 38. An improved thermal energy utilization process using arefrigeration system having a water tank, a pump, a heat exchanger, anda compressor, the process comprising: controlling head pressure of thecompressor using fluid in a first circulating loop so as to protect thecompressor and maintain acceptable compressor efficiency.
 39. Theimproved process of claim 38 further comprising controlling refrigerantsubcooling using fluid in a second circulating loop so as to increasecompressor efficiency and increase cooling and heating capacity.
 40. Theimproved process of claim 38 further comprising a heat path which isutilized to heat a liquid before any heat is rejected from the process.41. The improved process of claim 38 wherein the process includes adesuperheating segment which is used to heat a fluid to a temperatureabove the condensing temperature of the refrigerant.
 42. The improvedprocess of claim 41 further comprising using a third circulating loop tocontrol desuperheating.
 43. An improved thermal energy utilizationprocess using a refrigeration system having a water tank, a pump, a heatexchanger, and a compressor, the process comprising: controllingrefrigerant subcooling using fluid in a first circulating loop so as toincrease compressor efficiency and increase cooling and heatingcapacity.
 44. The improved process of claim 43 further comprisingcontrolling head pressure of the compressor using fluid in a secondcirculating loop so as to protect the compressor and maintain acceptablecompressor efficiency.
 45. The improved process of claim 43 furthercomprising a heat path which is utilized to heat a liquid before anyheat is rejected from the process.
 46. The improved process of claim 43wherein the process includes a desuperheating segment which is used toheat a fluid to a temperature above the condensing temperature of therefrigerant.
 47. The improved process of claim 46 further comprisingusing a third circulating loop to control desuperheating.
 48. A methodof balancing a thermal energy recovery system, comprising: determining adesired level of thermal energy change at a specific location; choosinga refrigerant to use in a refrigeration system; determining how manyevaporators to use in the system; determining how many condensers to usein the system; selecting a compressor for the refrigeration system;calculating energy losses from the evaporators, condensers andcompressor; and maximizing the utilization of both heating and coolingresources during operation of the refrigeration system.